Roller counter

ABSTRACT

A roller counter, which can be reset to zero position via its axis has, for the purpose of stepping its digit rollers, a lock pawl swivellably supported on a side wall of the digit rollers for being swivelled around a pin. A pestle, serving the purpose of zero setting, is supported for swivelling movement around a second pin on the digit roller and cooperates with a stop on the axis. The locking pawl and the pestle each are spring-loaded to a predetermined degree by a leg of a leaf spring bent to V-shape. The leaf spring is held on the digit roller by means of a mounting including walls accompanying both legs of the leaf spring at the inner side and at the outer side and contacting the legs according to a surface-to-surface contact.

BACKGROUND OF THE INVENTION

b 1. Field of the Invention

This invention relates to roller counters including at least two digitrollers arranged on a common axis.

2. Description of the Prior Art

Roller counters are in particular used as kilometer counters or mileagecounters for vehicles but are also used as counters in sound recorders,video recorders and so on. In a known construction of such a rollercounter, the leaf spring provided for each roller is maintained on thedigit roller by means of protrusions designed like pins, some of thepins facing the inner side of the spring and some of the pins facing theouter side of the spring. It has been found that this provides for asecure positioning of the leaf spring but not for a definitepredetermined position of the spring in all counters. As a consequence,the initial stress by which the legs of the leaf spring make contactwith the pestle and, respectively, the lock pawl, is subject to widevariations from digit roll to digit roll. The result is that thestepping procedure and, respectively, the zero stepping procedure isinexact, resulting in reading errors.

SUMMARY OF THE INVENTION

It is an object of the invention to improve the mounting of the leafspring on the digit roller of a roller counter such that the leaf springcontacts the lock pawl and the pestle with a predetermined initial forceso that both these component parts are loaded with a predeterminedpre-load and, thus, experience the same pre-load conditions for alldigit rollers of the roller counter as well as for roller counters ofthe same construction.

This object of the invention is achieved by forming the protrusions intowalls contacting the leaf spring and accompanying both legs of the leafspring at its outer side as well as its inner side. A further wall isalso provided at the outer surface of the bent area of the leaf springand accompanies the bend of the leaf spring. In the constructionaccording to the invention, there is, thus, always a surface in contactbetween the wall protrusions and the leaf spring, whereas contact isalways only a line contact in the initially described known prior artconstruction. During assembly, the leaf spring is brought into adefinite predetermined position, so that the leaf spring contacts withits legs the pestle and, respectively, the lock pawl with a definitepredetermined pre-load even if the leaf spring has a varying angularaperture of both legs due to production tolerances. The wallsaccompanying the inner surface and the outer surface, respectively, ofthe leaf spring provide for a definite mounted position of the leafspring so that any mis-assembling is prevented.

According to a preferred embodiment of the invention, both legs of theleaf spring are, up to the beginning of the bent area, accompanied bytwo equal wall pairs and the outer walls of these wall pairs are joinedtogether in a manner arcuately extending around the bent area. In thismanner, there results a pocket-like seat for the leaf spring whichfacilitates assembly of the leaf spring, on the one hand, and maintainsthe leaf spring in position in an optimum manner, on the other hand. Asymmetrical design of both wall pairs is particularly suitable for leafsprings of symmetric design, i.e., leaf springs having legs of equallength, because in this case each leg of the leaf spring can be put intoeach slot formed of both wall pairs, so that the leaf spring can beinserted into its mounting at the digit roller in each of both possiblepositions.

According to a further embodiment of the invention, the arrangement issuch that, within the area of the apex of the bent area, the wall facingthe inner side of the leaf spring is relieved relative to the leafspring, so that within this area the leaf spring is not contacted at itsinner side by a wall. It has in some cases been found that the leafspring tends to experience an uprising movement if the wall pairscontinuously follow the curvature of the leaf spring.

According to the invention, the walls maintaining the leaf spring inposition may carry protrusions extending beyond the cross section of theleaf spring for being pinched in order to extend over the cross sectionof the leaf spring. In this manner, the leaf spring is prevented fromleaving its mounting. Suitable pinchable materials are in particularsynthetic plastic materials which form, as a rule, the digit rollers andare known in the prior art.

The present invention has non-rotatably supported bearing platesarranged between the digit rollers for bearingly supporting steppingpinions coordinated to the digit rollers. Each of the stepping pinionsis driven by a teeth pair of the digit roller and is in meshingengagement with a cog of a ring bearingly supported on a collar of thesecond or, respectively, each following digit roller. The roller counterhas a plurality of inwardly facing recesses, one of which is engaged bya spring-loaded lock pawl supported on the digit roller which serves thepurpose of fixing the position of the ring relative to the digit rollerfor the purpose of zero setting all digit rollers. The axis of theroller counter is rotatable and each digit roller has a stop whichstrikes, during zero setting of the axis, a spring-loaded pestleswivellably supported on the digit roller. The spring-loaded pestle andthe lock pawl are loaded by one leg each of a leaf spring bent into aV-shape or, alternatively, a U-shape, where the leaf spring is heldwithin the area of its bend by lateral protrusions of the digit roller.

The arrangement according to the invention can further be such that eachof the lock pawl and the pestle are supported with a bearing bore on onepin each of the digit roller. These pins carry cams extending in normalrelation to the pin axis and engage recesses in the bearing bore. Theserecesses are larger than the cams for the amount of the swivelling areaof the lock pawl and, respectively, the pestle, and the cam associatedwith the pestle is directed in a direction other than the cam associatedwith the recess. In this manner, it is simple to prevent, duringassembly, the pestle and the lock pawl from being mounted ininterchanged position, which occurred in known constructions, on accountof the similarity of both component parts and which can result incomplications during operation.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing, the subject of the invention is schematicallyillustrated with reference to examples of the preferred embodiment.

FIG. 1 shows a cross section along the central axis of a basicconstruction of the roller counter;

FIG. 2 shows a side view of a digit roller along the axial directiontogether with the component parts supported thereon;

FIG. 3 is a plan view showing in an enlarged scale the walls holding theleaf spring;

FIG. 4 is a section view along line IV--IV of FIG. 3; and

FIG. 5 shows a section view similar to that of FIG. 4 but with themounted leaf spring being maintained in position by pinched protrusions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The roller counter shown in FIG. 1 has, in its basic construction, fourdigit rollers 1 corresponding to the individual decimal values of anumber to be displayed having four places. The digit rollers are seatedon a common central axis 2 by means of central collars 3 which allow forrotation. One collar 3 is elongated in the axial direction in case ofthe digit roller 1 which registers the lowest numeral place, theelongation forming the bearing support for a tooth gear 4, which drivesthe roller counter during operation and which is prevented from beingdrawn off the collar 3 by a flange 5 on the axis 2. The tooth gear 4drives the first digit roller 1 in one direction that is, for summingup, by means of a lock pawl 6 which is swivellably supported on a pin 7,as shown in FIG. 2, of the digit roller 1. Stepping operation from onedigit roller 1 to the next digit roller is effected via a steppingpinion 8 which is rotatably supported on a bolt 9 of a profiled bearingplate 10 arranged between two mutually adjacent digit rollers 1 andsupported on the collars of the adjacent digit roller 1. Each of thebearing plates 10 is provided outside of the periphery of the digitrollers 1 with a pin 11 axially protruding in a direction to one sideand snugly engaging a corresponding bore of a bushing 12 extending fromthe bearing plate 10 in an opposite direction relative to the pin 11.The bearing plates 10 are, thus, coupled one with the other and areprevented from rotation, because the pin 11, illustrated in FIG. 1 atthe extreme left-hand side, engages a stationary rest, not shown.

Each stepping pinion 8 is driven by a dog formed of two teeth 13 of theimmediately adjacent digit roller 1 and drives in its turn a ring 14located adjacent the stepping pinion 8. The ring 14 has gearing 15 whichcommunicates with the teeth of the stepping pinion 8. The ring 14 isrotatably supported on the collar 3 of the subsequent digit roller 1 andcarries at its side located opposite the gearing 15 a series of teninwardly facing recesses 16 shown in FIG. 2. One of these recesses 16 isengaged by the lock pawl 6 of the adjacent digit roller 1. The lock pawl6 is pre-loaded by a leaf spring 17, as shown in FIG. 2, so that thering 14 is held in the correct position and can be rotated in only onedirection relative to the digit roller 1. During rotation of the ring 14in this one direction, the lock pawl 6 slides out of its respectiverecess 16 and slips over the inner circumference of the circumferentialwall, which is provided with the recesses 16, of the ring 14, until thelock pawl 6 falls into the next recess 16 under the pre-load of the leafspring 17. Rotation of the ring 14 in the other direction is preventedby giving a suitable shape to the recesses 16 which are engaged by anose 18 of the lock pawl 6.

Zero-setting of the roller counter is effected by rotating the centralaxis 2, shown in FIG. 2, counterclockwise. The central axis has, foreach digit roller, a stop 19 formed by a nose configured by a depression20 in the axis 2 and has, as seen in the Figure, an angle at 90° . Apestle 21, shown in FIG. 2, also pre-loaded by the leaf spring 17, fallsinto the depression 20. The pestle is pivotally supported on a pin 22,laterally protruding from the side wall of the digit roller 1. In normaloperation, the digit roller 1 rotates counterclockwise, as seen in FIG.2, so that the pestle 21 slides along the circumference of the axis 2,and is stationary in this condition. If, however, the axis 2 is rotatedcounterclockwise, the pestle 21 falls into the depression 20, so thatthe stop 19 of the axis 2 moves the pestle forwardly in its longitudinaldirection and, thus, transfers the digit roller 1 into zero position.

The lock pawl 6 and the pestle 21 each are pre-loaded by one respectiveleg 23 of the leaf spring 17 which contacts the pestle 21 and,respectively, the lock pawl 6 with a predetermined initial load. Forthis purpose, the leaf spring 17, which is bent to be V-shaped orU-shaped and has legs of equal length, is held within a mounting 24 ofthe side wall of the digit roller 1. The mounting 24 is formed of walls25 and 26 arranged inside and outside on the leaf spring 17. The wallsare in surface contact with the leaf spring 17, and the walls arearranged within the area of the bent portion 27 of the leaf spring 17 soas to contact both legs 23. The inner wall 25 and the outer wall 26,thus, form a gap located between them for snugly receiving therespective legs 23 of the leaf spring 17. Both outer walls 26 are joinedby a further wall 26', so that they continuously follow the leaf spring17 at the outer side of the bent portion 27 of the leaf spring 17. Thepocket formed thereby serves to reliably hold the leaf spring 17 inplace. At the inner side of the bent portion 27 of the leaf spring 17,the inner walls 25 adjoin the leaf spring 17 only up to the beginning ofthe bent portion 27, so that the bent portion 27 is kept free of wallsat its inner side. The orientation of the slots delimited by the walls25 and 26 for receiving both the legs 23 of the leaf spring 17 isselected such that the leaf spring 17 contacts with its legs 23 the lockpawl 6 and the pestle 21 with a predetermined pre-load which presses thelock pawl 6 into the locking position in which the lock pawl 6 engageswith its nose 18 one of the recesses 16. This tensioned position of theleaf spring 17 is shown with full lines in FIG. 2, whereas the relaxedposition of both legs 23 of the leaf spring 17 is shown in dashed lines.

As shown in FIG. 2, both the pins 7 and 22, by means of which the lockpawl 6 and the pestle 21 are swivellably linked on the digit roller 1,are provided with a cam 28 protruding in normal relation to the pinaxis. This cam 28 slides, during the swivelling movement of the lockpawl and the pestle 21, within a recess 29 of a bearing bore 30, withwhich the lock pawl 6 and, respectively, the pestle 21 are seated bymeans of the respective pins 7 and 22. The cam 28 of the pin 7 isdirected in a direction other than that of the cam 28 of the pin 22.Both recesses 29 are arranged such that the aforementioned swivellingmovements of the lock pawl 6 and of the pestle 21 are possible withadequate play. Thus, the pestle 21 and the lock pawl 6 are preventedfrom being mutually interchanged during assembly, because thesecomponent parts can never be mounted in an incorrect manner on accountof the differing directions in which the cams 28 are oriented inconnection with the profile shape of the lock pawl 6 and of the pestle21.

For securing the leaf spring 17 against falling out of its mounting,there are provided on the outer wall 26 of the mounting 24 for the leafspring 17, as shown in FIGS. 4 and 5, protrusions 31 which extend beyondthe cross section of the leaf spring and can be pinched over this crosssection, starting from the original shape shown in FIG. 4, to thepinched final shape, shown in FIG. 5. In the pinched final shape, theprotrusions 31 extend over the leaf spring 17, so that this springcannot fall out of the groove delimited by the walls 25 and 26. Theprotrusions 31 are conveniently arranged at those ends of the walls 25and 26, which have the greatest distance from the bent portion 27.

In special cases, the digit rollers 1 may carry symbols in place ofdigits, for example letters.

The set of digit rollers 1 and of bearing plates 10 are secured againstbeing drawn off by a circlip 32 put onto the axis 2.

Although the best mode contemplated by the inventor for carrying out thepresent invention as of the filing date hereof has been shown anddescribed herein, it will be apparent to those skilled in the art thatsuitable modifications, variations, and equivalents may be made withoutdeparting from the scope of the invention, such scope being limitedsolely by the terms of the following claims.

I claim:
 1. A roller counter, comprising:an axle member; at least twodigit rollers rotatably supported by said axle member; a teeth pairintegral with each digit roller of said at least two digit rollers; aplurality of stepping pinions, one of said plurality of stepping pinionsrespectively for each said at least two digit rollers, each of saidplurality of stepping pinions being bearingly supported on said axlemember, said plurality of stepping pinions engaging said teeth pair fordriving one of s aid at least two digit rollers; a plurality of bearingplates fixedly attached to said axle member, each of said bearing platesbeing located on said axle member between adjacent digit rollers of saidat least two digit rollers, each of said plurality of hearing platesbearingly supporting respectively each of said plurality of steppingpinions; at least one collar, said at least one collar beingnon-rotatably mounted between said at least two digit rollers and s aidaxle member; at least one ring bearingly supported by said at least onecollar, said at least one ring having a toothed surface in gearingengagement with one of said plurality of stepping pinions of arespective digit roller, said at least one ring further having a centerfacing surface having a plurality of center facing recesses; a lock pawlsupported on each of said at least two digit roller, respectively, saidlock pawl engaging one of said plurality of center facing recesses fororienting said at least one ring in a fixed direction relative to arespective digit roller; and zero setting means for zero setting said atleast two digit rollers, said zero setting means comprising:a leafspring having a bent portion forming two legs on either side thereof,said two legs having an inside surface generally facing each other, saidtwo legs having an outside surface generally facing away from eachother, one leg of said leaf spring biasing said lock pawl towards saidplurality of center facing recesses; at least two stop notches in saidaxle member, one of each of said at least two stop notches being locatedrelative to one of each of said at least two digit rollers; pestle meansswivellably supported on said at least one ring, said pestle means beingbiased toward said axle member by the other leg of said two legs of saidleaf spring; and lateral protrusions on each of said at least two digitrollers for holding said leaf spring in a predetermined location, saidlateral protrusions forming walls contacting said two legs, said lateralprotrusions having an outer well contacting a portion of said outsidesurface of each said two legs of said leaf spring, said lateralprotrusions further comprising a contiguous wall portion contacting saidleaf spring along said bent portion, said lateral protrusions furthercomprising an inner wall contacting a portion of said inside surface ofeach said two legs of said leaf spring, said lateral protrusions furtherhaving protrusions extending beyond said leaf spring to permit pinchingsaid protrusions over said leaf spring for holding said leaf spring toone of said at least two digit rollers.
 2. The roller counter of claim1, wherein said lateral protrusions contact said two legs on both saidinside and said outside surfaces.
 3. The roller counter of claim 2,wherein said lateral protrusions follow symmetrically each of said twolegs of said leaf spring.
 4. The roller counter of claim 1, wherein atsubstantially the apex of said bent portion of said leaf spring, saidwall portion contacting said leaf spring along said bent portion isrelieved from said inside surface so that said leaf spring is notcontacted thereat by said wall portion.
 5. The roller counter of claim1, wherein said two legs of said leaf spring are of substantially equallength.
 6. The roller counter of claim 1, wherein said bent portion ofsaid leaf spring is formed by said leaf spring being bent into aV-shape.
 7. The roller counter of claim 1, wherein said bent portion ofsaid leaf spring is formed by said leaf spring being bent into aU-shape.
 8. The roller of claim 1, wherein said at least two stopnotches are each formed a depression in said axle member.
 9. The rollercounter of claim 1, wherein each said at least two digit rollers has atleast two bearing bores, one each for mounting said lock pawl and saidpestle means, each said bearing bore having a recess, and wherein saidroller counter further comprises a pin inserted in each said bearingbore of each said digit roller; anda cam located on each said pin, eachsaid cam extending radially outward from each said pin for engaging saidrecess of said bearing bore in which each said pin has been inserted,each said recess being dimensionally larger than each said cam by anamount that allows said pestle means to swivel between each said stopnotch and said periphery of said axle member, and respectively allowssaid lock pawl to swivel from each said center facing recess to saidcenter facing surface of said at least one ring, said cam on said pinfor said pestle means being oriented in a direction other than that ofsaid cam of said pin for said lock pawl.
 10. The roller counter of claim3, wherein at substantially the apex of said bent portion of said leafspring, said wall portion contacting said leaf spring along said bentportion is relieved from said inside surface so that said leaf spring isnot contacted thereat by said wall portion.
 11. The roller counter ofclaim 2, wherein at substantially the apex of said bent portion of saidleaf spring, said wall portion contacting said leaf spring along saidbent portion is relieved from said inside surface so that said leafspring is not contacted thereat by said wall portion.
 12. The rollercounter of claim 2, wherein said bent portion of said leaf spring isformed by said leaf spring being bent into a U-shape.
 13. The rollercounter of claim 3, wherein said bent portion of said leaf spring isformed by said leaf spring being bent into a U-shape.
 14. The rollercounter of claim 12, wherein said at least two stop notches are eachformed by a depression in said axle member.
 15. The roller counter ofclaim 13, wherein said at least two stop notches are each formed by adepression in said axle member.
 16. The roller counter of claim 15,wherein each said at least two digit rollers has at least two bearingbores, one each for mounting said lock pawl and said pestle means, eachsaid bearing bore having a recess, and wherein said roller counterfurther comprises a pin inserted in each said bearing bore of each saiddigit roller; anda cam located on each said pin, each said cam extendingradially outward from each said pin for engaging said recess of saidbearing bore in which each said pin has been inserted, each said recessbeing dimensionally larger than each said cam by an amount that allowssaid pestle means to swivel between each said stop notch and saidperiphery of said axle member, and respectively allows said lock pawl toswivel from each said center facing recess to said center facing surfaceof said at least one ring, said cam on said pin for said pestle meansbeing oriented in a direction other than that of said cam of said pinfor said lock pawl.
 17. The roller counter of claim 14, wherein eachsaid at least two digit rollers has at least two bearing bores, one eachfor mounting said luck pawl and said pestle means, each said bearingbore having a recess, and wherein said roller counter further comprisesa pin inserted in each said bearing bore of each said digit roller; andacam located on each said pin, each said cam extending radially outwardfrom each said pin for engaging said recess of said bearing bore inwhich each said pin has been inserted, each said recess beingdimensionally larger than each said cam by an amount that allows saidpestle means to swivel between each said stop notch and said peripheryof said axle member, and respectively allows said lock pawl to swivelfrom each said center facing recess to said center facing surface ofsaid at least one ring, other than that of said cam of said pin for saidlock pawl.